fuzzing.yml: Bump GNU coreutils to 9.11

[oech3]

attempt to close #12512
#12512 (comment)

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/date/date-locale-hour (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/tail-n0f (fails in this run but passes in the 'main' branch)
Congrats! The gnu test tests/cp/sparse-to-pipe is no longer failing!
Note: The gnu test tests/cut/bounded-memory is now being skipped but was previously passing.
Note: The gnu test tests/cut/cut-huge-range is now being skipped but was previously passing.
Note: The gnu test tests/expand/bounded-memory is now being skipped but was previously passing.

[codspeed-hq]

Merging this PR will not alter performance

✅ 331 untouched benchmarks
⏩ 46 skipped benchmarks¹

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_{Comparing oech3:fuzz-gnu (183d5ea) with main (d967066)}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩